1. Field of the Invention
The present invention relates to an apparatus and method for forming arrays of articles for subsequent packaging. More particularly, the present invention provides an array forming apparatus and method wherein the articles are positioned in the arrays in varying orientations.
2. Description of Related Art
Many consumer products or other articles are not of a uniform or symmetrical shape, and thus the packaging of these items can be problematic. If these products are not packaged in an optimal manner, package strength and integrity may suffer and an excessive amount of packaging material may be needed to compensate for such shortcomings. In addition, the resulting package may not be consumer-friendly. It is also usually desirable to load as many articles as possible into a package of a given size in order to minimize slack space. When the articles are not uniform in size, optimal packaging often requires that the articles be packaged in a non-uniform manner. Non-uniform packaging, however, is difficult to accomplish in an automated, mechanical production/packaging process.
One particular type of asymmetrical articles having unique packaging difficulties are absorbent articles such as diapers, adult incontinence pads, sanitary napkins and pantiliners. These products are often profiled, particularly diapers and adult incontinence pads, such that the crotch portion of the products is much thicker than the waist area due to the additional absorbent material placed near the likely areas of discharge. This difference in thickness is even more pronounced when diapers or incontinence pads are packaged, since each diaper or pad is typically folded in half prior to insertion into an outer package. In addition, the diapers or pads are usually compressed prior to insertion into the package, and differences in compressibility caused by the profiling of these products may create additional packaging difficulties.
Diapers, adult incontinence pads, and similar articles typically are produced in sequential fashion such that the articles leave the production area one after another along a conveyor system. In the case of diapers and adult incontinence pads, these products typically leave the production area lying flat on a moving transport device such as a conveyor belt. The diapers or pads are then folded in half, and then rotated to an upright position. In this upright position, the diapers or pads are transported serially with the folded nose portion (referred to herein as the proximal end) leading. The diapers or pads are then deposited into an array forming apparatus which compiles a predetermined number of diapers or pads into an array (or stack) for packaging purposes. This array forming apparatus, often referred to as a stacker or accumulator, converts a series of products advancing sequentially along a conveyor system into an array (or stack) comprising a plurality of the diapers or pads positioned side by side. The product array may then be advanced onward to further packaging steps. Exemplary stacking devices are shown in U.S. Pat. Nos 3,954,165, 4,325,475 and 5,474,168.
In the prior art methods, the diapers or pads of an array are arranged therein in an identical, side by side orientation. For example, each diaper present in an array leaving a stacker is typically in a nose forward orientation. The region of the array corresponding to the nose portions of the diapers therein will often be thicker due to profiling of the diaper core, and the compressibility of the array will not be uniform across due to the pad profiling. Prior art stackers, however, are generally incapable of providing arrays wherein the orientation of the articles alternates within the array.
The present invention provides an apparatus and method for producing arrays of products wherein each product of an array may have one of two distinct orientations, and the orientation of the articles within a particularly array may therefore be varied as desired.